System and method for the collection of spectral image data

ABSTRACT

A method of verifying the contents of a package comprising obtaining a spectral image of a first package, the first package having a plurality of receptacles configured to receive an item, wherein the plurality of first package receptacles do not contain any items, acquiring a spectral image of a second package, the second package having a plurality of receptacles configured to receive an item, wherein the plurality of second package receptacles each contain an item, and comparing the spectral image of the first package with the spectral image of the second package wherein acquiring a spectral image of a second package comprises acquiring a plurality of spectral image lines and wherein each of the spectral image lines comprises a plurality of image pixels.

RELATED APPLICATIONS

The present application claims priority to U.S. provisional applicationNo. 60/268,483 and titled NIR Screening of Materials To Be Packaged,filed on Feb. 12, 2001, which is hereby incorporated by reference.

The present application is based on disclosure document No. 481228deposited with the U.S. Patent and Trademark Office on Oct. 17, 2000.The present application is also related to U.S. patent application Ser.No. 10/023,302, filed on even date herewith and titled System and Methodfor Combining Reflectance Data, and U.S. patent application Ser. No.10/023,395, filed on even date herewith and titled System and Method forGrouping Reflectance Data. Each of the above documents are herebyincorporated by reference.

FIELD OF THE INVENTION

The present invention pertains to spectrometer and reflectance dataanalysis and more particularly to the screening and identification ofmaterials such as pharmaceutical or food products being packaged in anautomated machine.

BACKGROUND OF THE INVENTION

Optical spectrometers allow the study of a large variety of samples overa wide range of wavelengths. Materials can be studied in the solid,liquid, or gas phase either in a pure form or in mixtures. Variousdesigns allow the study of spectra as a function of temperature,pressure, and external magnetic fields.

Near-Infrared (NIR) spectroscopy is one of the most rapidly growingmethodologies in product analysis and quality control. In particular,NIR is being increasingly used as an inspection method during thepackaging process of pharmaceuticals or food products. More and moreoften, this technique is augmenting or even replacing previously usedvision inspection systems. For example, an NIR inspection system can beused to inspect a pharmaceutical blister package (such as an oralcontraceptive or allergy medication) for, among other things, physicalaberrations, chemical composition, moisture content, and proper packagearrangement.

Most notably, NIR spectrometry inspection systems can be used toevaluate the chemical composition of products during the packagingprocess. Particularly with solid dosage pharmaceutical products, a groupor package of products may look identical in the visible portion of thespectrum but may have unique chemical signatures in the near-infraredrange (e.g. the 800-2500 nm range). Variations in the chemicalcomposition of a tablet or capsule are usually grounds for rejecting apackage containing a tablet with such a discrepancy. In operation on apharmaceutical blister packaging machine, a still uncovered blister packcontaining tablets or capsules passes an inspection station where it isexamined. Once the inspection device inspects the blister pack to ensurethat the correct material is located in each of the tablet or capsulewells, the packaging machine seals the blister pack. Those packages thatfail the inspection process are rejected at a subsequent station.Subject to regulatory requirements, the rejected tablets may also berecycled for further processing.

The use of vision systems as an inspection mechanism continues to becomeless desirable as the need for more in depth inspection procedures andnear 100% inspection processes are desired. Of particular concern isthat known vision systems are inherently incapable of performing achemical analysis of the product being packaged. Rather, vision systemsrely solely on a comparison of a visual snapshot of the package to apreviously stored reference image. Known vision packaging inspectionsystems “look” at each individual package to see whether it has thecorrect number of doses in the pack. For example, vision systems lookfor missing or overfilled tablet wells. In some cases, physicaldiscrepancies, cracks, or gouges on a tablet will also cause a visionsystem to reject the package. What may not be detected by a visionsystem is the situation where each of the products in a package appearsto be similar and in conformance with a reference image but theformulation of one or more products within the package are incorrect, orthe wrong product composition is inserted into the packaging. Thelimitations of these types of known visions systems become readilyapparent when higher levels of inspection are required and when they arecompared with the expanded capabilities of a spectrometer-basedinspection system.

Even though spectrometer-based monitoring and inspection systems arebecoming more prevalent, many of them still have limited capabilities.These limitations are primarily due to the requirement that each tabletor capsule in a package be independently inspected by the spectrometersystem. Therefore, a conventional spectrometer can only look at andanalyze one sample at a time. Thus, the larger the number of productsthat are being inspected, the longer it will take to perform theinspection. Adding additional spectrometers is not a preferred solutionbecause of the costs and maintenance issues associated with theincreased hardware. Since spectrometer-based systems are meant in largepart to replace vision systems, both accuracy and speed remain importantfactors when utilizing such systems. Thus, it would be desirable to havea spectrometer-based inspection system that can maintain the throughputof traditional vision systems without sacrificing the ability to performaccurate chemical composition analysis and without requiring theaddition of expensive and problem prone equipment.

In many cases, multiple formulations are packaged into a single blisterpack. Therefore, it is also desirable to have a spectrometer-basedinspection system that can detect when an item is in the wrong locationwithin the larger package that is being inspected while at the same timerealizing the benefits of a spectrometer based inspection system.

Finally, it is desirable to have a spectrometer-based inspection systemthat can execute a self-referencing calibration in order to obtainconforming data to compare with during an inspection process as well asto determine item locations from a previously unknown package layout.

SUMMARY OF THE INVENTION

In one aspect, a method of verifying the contents of a package comprisesobtaining a spectral image of a first package, the first package havinga plurality of receptacles configured to receive an item, wherein theplurality of first package receptacles do not contain any items,acquiring a spectral image of a second package, the second packagehaving a plurality of receptacles configured to receive an item, whereinthe plurality of second package receptacles each contain an item, andcomparing the spectral image of the first package with the spectralimage of the second package wherein acquiring a spectral image of asecond package comprises acquiring a plurality of spectral image linesand wherein each of the spectral image lines comprises a plurality ofimage pixels.

In another aspect, a method of verifying the location of packagecontents comprises acquiring a reflectance signal of a package, thepackage having a plurality of receptacles configured to receive an item,wherein each of the plurality of receptacles contains an item, whereinthe reflectance signal comprises a plurality of image pixels, isolatingthe image pixels that correspond to each of the plurality of items, andcomparing the reflectance signal of the isolated image pixels with areference reflectance signal.

In a further aspect, a push-broom scanning spectrometer, comprises animager adapted to simultaneously acquire a line of image pixels from amoving package, wherein the image pixel line comprises a plurality ofcontiguous spectral bands, wherein the image pixel line is orientedperpendicular to the direction of motion of the package, wherein thepackage includes a plurality of items, a conveyer system adapted to movethe package through a field of view corresponding to the imager, and aprocessor capable of being programmed to compare the line of imagepixels with a references signal and to determine the location of theplurality of items within the package based on the comparison of theline of image pixels to the reference signal.

As will become apparent to those skilled in the art, numerous otherembodiments and aspects will become evident hereinafter from thefollowing descriptions and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate both the design and utility of the preferredembodiments of the present invention, wherein:

FIG. 1 is a general overview of an inspection system;

FIG. 2 is a diagram of a first embodiment of an inspection headconstructed in accordance with the present invention;

FIG. 3 is a schematic representation of the inspection head of FIG. 2;

FIG. 4 is a diagram of a second embodiment of an inspection headconstructed in accordance with the present invention;

FIG. 5 is a schematic representation of the inspection head of FIG. 4;

FIG. 6 is a diagram of a further embodiment of an inspection headconstructed in accordance with the present invention;

FIG. 7 is a schematic representation of the inspection head of FIG. 6;

FIG. 8 is a diagram of a light energy aggregator constructed inaccordance with an embodiment of the present invention;

FIGS. 9-12 are details of a splitter block constructed in accordancewith an embodiment of the present invention;

FIGS. 13-15 are perspective diagrams of an inspection head constructedin accordance with various aspects of the present invention;

FIGS. 16 and 17 are flow charts depicting inspection methods inaccordance with various embodiments of the present invention;

FIG. 18 is a cross-section of a scanning spectrometer system constructedin accordance with an embodiment of the present invention;

FIGS. 19A-19C are plan views of a package at various stages of aninspection system constructed in accordance with an embodiment of thepresent invention; and

FIG. 20 is a flow chart depicting a method in accordance with anembodiment of the present invention.

DETAILED DESCRIPTION

FIG. 1 depicts an inspection system 100. The inspection system 100 isgenerally arranged to allow the inspection of a product, for exampletablets or capsules 130, that have been loaded into a package 125. Asshown in FIG. 1, the packages 125 move along a conveyer 120 mountedwithin a filling unit 105. The filling unit 105 is preferably onecomponent of a larger manufacturing and packaging system. As an example,such manufacturing and packaging systems are typically utilized inpharmaceutical and chemical manufacturing facilities, although similarsystems are often utilized in other applications such as food processingand consumer product facilities. Aspects of the present invention can beapplied to virtually any of these applications. For purposes ofillustration only, the present invention will be described inconjunction with a pharmaceutical packaging system used to seal tabletsor capsules in a blister-type package. Also shown in FIG. 1, andincluded as a component of the inspection system 100, is an inspectionhead 110 constructed in accordance with various aspects of the presentinvention.

The inspection head 110 bridges the conveyer 120 that carries thepackages 125. The inspection head 1 10 includes an array of sampleprobes 115 extending downward from the inspection head 110 andsubstantially aligning with the items 130 contained in the passingpackages 125. Generally, a light source (not shown) illuminates thepackages 125 including the tablets 130 as they pass under the inspectionhead 110 and the sample probes 115. Light is reflected by the tablets130 and the reflected light energy is gathered by one or more of theprobes 115. In the general arrangement of FIG. 1, a single sample probe115 corresponds to a single tablet. Either the web of packages 125 movesin steps, where the step increment matches the size of the packages inthe direction of motion, or the web moves continuously. In the steppedprogression, item inspection occurs when the package web is stationary.In the continuous progression, item inspection occurs during the timeinterval when the items are in the field of view of the probes 115. Asdiscussed below, various other arrangements of the sample probes arecontemplated by an inspection system constructed in accordance with thepresent invention.

The reflected light energy gathered by each of the probes 115 isanalyzed to determine specific properties of each of the tablets 130that pass beneath the inspection head 110. Light energy gathered by thesample probes 115 is then directed through fiber optic cables, to aspectrometer that may be housed within the inspection head 110 (notshown). The collected light energy is analyzed by the spectrometeraccording to predetermined criteria. The information generated by thespectrometer is then forwarded via a data cable 140 to a computer 135for display, storage, or further analysis. The computer 135 may bepreloaded with processing information pertaining to the specificpackaging or inspection operation being conducted. The informationgathered about the tablets 130 contained in each package 125 may then beused to determine whether the specific tablets being inspected conformwith a predetermined quality criteria.

By gathering spectrographic data about each of the tablets 130, adetermination can be made as to whether the packages have been properlyfilled or contain the proper product. Spectrographic analysis alsoallows other determinations to be made that are not available with knownvision-based systems, such as proper pharmacological composition, watercontent, and other chemical and physical properties.

FIG. 2 shows in further detail a diagrammatic representation of a lowerportion of the inspection head 110, and more particularly, the array ofsample probes and how they interact with the tablets passing along theconveyer 120. The probe array is generally referred to in FIG. 2 asreference number 200. In the example of FIG. 2, a product package 215,such as a filled but yet un-sealed blister package, contains fifteen(15) individual tablets in a three-by-five arrangement. Various otherarrangements of the tablets are contemplated and the three-by-fivearrangement of FIG. 2 is shown merely as an example. The tablets in thepackage 215 are arranged into five columns. From left to right in FIG.2, column one includes tablets 225 a, 225 b, and 225 c, column twocontains tablets 230 a, 230 b, and 230 c, column three contains tablets235 a, 235 b, and 235 c, column four contains tablets 240 a, 240 b, and240 c, and column five contains tablets 245 a, 245 b, and 245 c.Corresponding to each of the fifteen tablets in FIG. 2 is a sampleprobe. From left to right, the sample probes also are divided into fivecolumns with three sample probes in each column. Column one containssample probes 325 a, 325 b, and 325 c, column two contains sample probes330 a, 330 b, and 330 c, column three contains sample probes 335 a, 335b, and 335 c, column four contains sample probes 340 a, 340 b, and 340c, and column five contains sample probes 345 a, 345 b, and 345 c. Asthe conveyer system moves the package 215 into position under theinspection head 110, the fifteen sample probes are positioned tocorrespond respectively to a similarly positioned tablet in the package215. Namely, the sample probes are positioned substantially above thecorrespondingly positioned tablet.

Each of the sample probes are connected to a fiber optic cable which inturn is connected to a light energy aggregator 350. In FIG. 2, thefifteen fiber optic cables are represented as reference numbers 250,255, 260, 265, 270, 275, 280, 285, 290, 295, 300, 305, 310, 315, and320. Each one of the fiber optic cables corresponds to a single sampleprobe and thus also corresponds to a light reading from thecorresponding tablet passing beneath the inspection head.

The light energy aggregator 350 operates to combine the light energygathered by each of the fifteen sample probes (via the fiber opticcables) and output the combined light energy through a single outputterminal. Further details of a preferred embodiment of a light energyaggregator constructed in accordance with the present invention aredescribed in conjunction with FIGS. 8-12. Briefly, the combined lightenergy from the light energy aggregator 350 is directed to an entranceslit on a spectrometer 355 where it is subsequently analyzed. Lightsources 220 a and 220 b illuminate the tablets as they pass beneath thesample probes.

In operation, the inspection head allows a system to evaluate whetherany of the fifteen tablets in the package 215 are misplaced, defective,missing, chemically non-conforming, or have another problem, whileutilizing a single spectrometer 355. As the packaging system begins arun, reflectance data is acquired from a known representative samplepackage of tablets as it passes beneath the tips of the sample probes,and statistics are compiled based on the combined spectra of the itemsbeing inspected. The representative package is of a known quality, andthis initial run is thus classified as a calibration run. Appropriatepreprocessing of the spectra such as smoothing or first or seconddifferencing is applied. During the normal inspection process associatedwith a packaging run, the spectrum of each group or package of tabletsis compared back to the representative spectra collected during thecalibration run. This comparison may be through principal componentanalysis in which the first two or more eigenvectors are calculated andapplied to the spectrum of each group of inspected items. Anothercomparison method relies on the dot product between the vectorcontaining values from each of the spectral wavelength channels in thecalibration run and the spectral vector of the package to be inspected.Any spectrum that deviates in its totality by more than a specifiednumber of standard deviations is deemed to contain foreign material anda signal is sent to the packaging machine causing the group ofitems/package in question to be rejected and removed from the linebefore final packaging. Further details of spectra comparisons, as wellas other methods of comparison, can be found in the Handbook ofNear-Infrared Analysis, Donald Bums and Emil W. Ciurczak, Marcel Dekker,Inc. 1992, the details of which are hereby incorporated by referenceinto the present application. Alternately, if reflectance values areknown for a particular item or package, this information can be inputdirectly into the inspection system and a calibration run becomesunnecessary.

Turning to FIG. 3, a schematic diagram of an inspection system 400constructed in accordance with the present invention is shown. Theschematic diagram of FIG. 3 generally corresponds to FIG. 2. The diagramof FIG. 3 represents how a number of different sample probes P₁-P_(N)can be utilized to obtain a spectrographic measurement from any numberof individual samples and feed the collected information to a singlespectrometer as a combined input. Based on the combined reading from allof the sample probes, an evaluation can be made as to whether a defect(either chemical or physical) exists somewhere in the package. Since acombined value is obtained, the package as a whole is analyzed for adefect rather than each particular tablet. If the package as a whole isdetermined to have a defect, that entire package can be rejected.Utilizing such a system allows faster analysis while utilizing a singlespectrometer thereby making the system as a whole less expensive andeasier to maintain.

With continuing reference to FIG. 3, Each of the sample probes P₁through P_(n), represented by reference numbers 405, 410, 415, 420, 425,430, 435, 440, and 445 are connected to a fiber optic cable, shown asreference numbers 407, 412, 417, 422, 427, 432, 437, 442, and 447respectively. The fiber optic cables are, in turn, connected to a lightenergy aggregator 450. The light energy aggregator 450 operates tocombine the light energy gathered by each of the fiber optic cables andoutput the combined light energy through a single output terminal.Further details of a preferred embodiment of a light energy aggregatorconstructed in accordance with the present invention are described inconjunction with FIGS. 8-12. Briefly, and as shown in FIG. 3, thecombined output light energy from the light energy aggregator 450 isdirected through a single fiber optic cable 455 and through an entranceslit 457 of a spectrometer 460. The combined light energy issubsequently analyzed by the spectrometer 460. A processor 465 iscoupled to the spectrometer 460 and further analyzes the combined lightenergy received by the spectrometer 460. The processor 465 then comparesthese results to a pre-determined or pre-assigned value that representsan acceptable measurement of the package (i.e. a package without anunacceptable level of defects). The comparison value can either beobtained by a calibration run as described above or can be input intothe processor based on known values. If the defect level does notconform to the comparison value, a rejection unit 470 coupled to theprocessor sends a signal to the packaging line to discard or remove thepackage with the defect.

The embodiment of the inspection system of FIGS. 2 and 3 utilizes asingle spectrometer to analyze the collective samples of fifteendifferent sample probes and thus can reject or accept a package based onwhether the package spectra as a whole meets a pre-determined criteria.As mentioned above, the use of a single spectrometer to evaluate theconformance of an entire package of tablets increases the speed of theinspection process while simultaneously reducing the cost of such aninspection system. However, the system of FIGS. 2 and 3 is unable todistinguish the precise location within the package of the foreignsubstance or damaged tablet. Often, it is desired to more accurately andprecisely locate the non-conforming tablet(s) from within each package.

Turning to FIG. 4, a diagrammatic representation of an inspection systemconstructed in accordance with a further aspect of the present inventionis shown. FIG. 4 shows in further detail a diagrammatic representationof the lower portion of an inspection head 110 used in conjunction withan inspection system, and more particularly, an array of sample probesand how they interact with the tablets passing along a conveyer. Theprobe array is generally referred to in FIG. 4 as reference number 500.In the example of FIG. 4, a product package 515, such as a filled butyet un-sealed blister package, contains fifteen (15) individual tabletsin a three-by-five arrangement. Various other arrangements of thetablets are contemplated and the three-by-five arrangement of FIG. 4 isshown merely as an example. The tablets in the package 215 are arrangedinto five rows. From left to right in FIG. 4, column one includestablets 525 a, 525 b, and 525 c, column two contains tablets 530 a, 530b, and 530 c, column three contains tablets 535 a, 535 b, and 535 c,column four contains tablets 540 a, 540 b, and 540 c, and column fivecontains tablets 545 a, 545 b, and 545 c. Corresponding to each of thefifteen tablets in FIG. 2 is a sample probe. From left to right, thesample probes also are divided into five columns with three sampleprobes in each column. Column one contains sample probes 625 a, 625 b,and 625 c, column two contains sample probes 630 a, 630 b, and 630 c,column three contains sample probes 635 a, 635 b, and 635 c, column fourcontains sample probes 640 a, 640 b, and 640 c, and column five containssample probes 645 a, 645 b, and 645 c. As the conveyer system moves thepackage 515 into position under the inspection head 110, the fifteensample probes are positioned to correspond respectively to a similarlypositioned tablet in the package 515. Namely, the samples probes arepositioned substantially above the correspondingly positioned tablet.

Each of the sample probes are connected to a fiber optic cable which inturn is connected to one of five different light energy aggregators 650,660, 670, 680, or 690. In FIG. 4, the fifteen fiber optic cables arerepresented as reference numbers 550, 555, 560, 565, 570, 575, 580, 585,590, 595, 600, 605, 610, 615, and 620. Each one of the fiber opticcables corresponds to a single sample probe and thus also corresponds toa light reading from the corresponding tablet passing beneath theinspection head.

Each of the light energy aggregators 650, 660, 670, 680, and 690operates to combine the light energy gathered by the three sample probes(via the fiber optic cables) that feed light energy into it. Each lightenergy aggregator then outputs the combined light energy through asingle output terminal. In the embodiment of FIG. 4, each of the lightenergy aggregators 650, 660, 670, 680, and 690 is associated with thefiber optic cables and sample probes from a single column. Morespecifically, light energy aggregator 650 receives light energy inputfrom fiber optic cables 550, 555, and 560, light energy aggregator 660receives light energy input from fiber optic cables 565, 570, and 575,light energy aggregator 670 receives light energy input from fiber opticcables 580, 585, and 590, light energy aggregator 680 receives lightenergy input from fiber optic cables 595, 600, and 605, and light energyaggregator 690 receives light energy input from fiber optic cables 610,615, and 620. Further details of a preferred embodiment of a lightenergy aggregator constructed in accordance with the present inventionare described in conjunction with FIGS. 8-12. Briefly, the combinedlight energy from each of the light energy aggregator's 650, 660, 670,680, and 690 is directed to an entrance slit on a correspondingspectrometer 655, 665, 675, 685, or 695 where it is subsequentlyanalyzed. Light sources 520 a and 520 b illuminate the tablets as theypass beneath the sample probes.

In operation, the inspection head allows a system to evaluate whetherone or more of the fifteen tablets in the package 515 are misplaced,defective, missing, chemically non-conforming, or otherwisenon-conforming. As the packaging system begins a run, reflectance datais acquired from a known representative sample package of tablets asthey pass beneath the tips of the sample probes and statistics arecompiled based on the combined spectra of the items being inspected. Therepresentative package is of a known quality and this initial run isthus classified as a calibration run. Preprocessing of the spectra isapplied in a similar manner as described above in conjunction with FIG.2, however, information is gathered on a column-by-column basis ratherthan on a whole-package-basis as in the embodiment of FIG. 2. In thismanner, if a defect or other abnormality is discovered within thepackage 515, the location of the defect can be narrowed down to aparticular column within the package allowing segregation of thedefective component and allowing more of the conforming tablets to bereused in the packaging run. Less waste and higher throughput istherefore realized.

Similarly, where blister packs contain more than one formulation, e.g.the package in FIG. 4 could have up to 5 formulations (one in each row),the system would be able to detect a misplaced tablet in any of thecolumns. Single spectrometer systems would not be able to detect when atablet in one row got inadvertently switched with a tablet in a secondrow having a different formulation. Probes from the multiplespectrometer system of FIG. 4 can be arranged in any configuration andnot just in rows as shown.

Turning to FIG. 5, a schematic diagram of an inspection system 700constructed in accordance with the present invention is shown. Theschematic diagram of FIG. 5 generally corresponds to FIG. 4. The diagramof FIG. 5 represents how a number of different sample probesP_(A1)-P_(E3) can be utilized to obtain a spectrographic measurementfrom any number of individual samples on a column-by-column basis andfeed the collected column-by-column information through a columnspecific light energy aggregator to a column-specific spectrometer as acombined input. Based on the combined reading from the sample probes ineach row, an evaluation can be made as to whether a defect (eitherchemically or physically) exists somewhere in the package. In the caseof a blister package containing tablets with several differentformulations, groups of probes feeding light to each of the light energyaggregators are positioned above the groups of tablets having a singleformulation. A further determination can be made as to which column thedefect or other abnormality resides. Since a combined value is obtainedfor each column of tablets, a particular column as a whole is analyzedfor a defect rather than each particular tablet. Thus, the system candetect when tablets with a given formulation are placed in the wrongrow. In many cases, any such formulation misplacement will cause theentire package to be rejected, however, it is contemplated that theotherwise conforming tablets can be salvaged and stored for later reuseor can be automatically placed back into the packaging line forinclusion in a subsequent package. Utilizing such a system allows fasteranalysis while requiring a fewer number of spectrometers thereby makingthe system as a whole less expensive and easier to maintain.

With continuing reference to FIG. 5, each of the sample probes P_(A1)through P_(E3), represented by reference numbers 702, 704, 706, 708,710, 712, 714, 716, 718, 720, 722, 724, 726, 728, and 730 are connectedto a corresponding fiber optic cable, shown as reference numbers 732,734, 736, 738, 740, 742, 744, 746, 748, 750, 752, 754, 756, 758, and 760respectively. The subscript designation in each of the probe labelsrefers to the column and row of each sample probe respectively. Namely,the letter designations, A, B, C, etc. refer to the first, second,third, etc. columns while the number designations 1, 2, and 3, refer tothe row designation in each column. Each one of the array of fifteensample probes can therefore be uniquely represented.

The column-by-column groupings of fiber optic cables are in turnconnected to a corresponding light energy aggregator 762, 764, 766, 768,or 770. Each of the light energy aggregators operate to combine thelight energy gathered by the fiber optic cables from a particular columnand output the combined light energy through a single output terminal.Further details of a preferred embodiment of a light energy aggregatorconstructed in accordance with the present invention are described inconjunction with FIGS. 8-12. Briefly, and as shown in FIG. 5, thecombined output light energy from the light energy aggregator 762 isdirected through a single fiber optic cable 771 and through an entranceslit 763 of a spectrometer 772. The combined light energy issubsequently analyzed by the spectrometer 772. The combined output lightenergy from the light energy aggregator 764 is directed through a singlefiber optic cable 773 and through an entrance slit 765 of a spectrometer774. The combined light energy is subsequently analyzed by thespectrometer 774. The combined output light energy from the light energyaggregator 766 is directed through a single fiber optic cable 775 andthrough an entrance slit 767 of a spectrometer 776. The combined lightenergy is subsequently analyzed by the spectrometer 776. The combinedoutput light energy from the light energy aggregator 768 is directedthrough a single fiber optic cable 777 and through an entrance slit 769of a spectrometer 778. The combined light energy is subsequentlyanalyzed by the spectrometer 778. The combined output light energy fromthe light energy aggregator 770 is directed through a single fiber opticcable 779 and through an entrance slit 781 of a spectrometer 780. Thecombined light energy is subsequently analyzed by the spectrometer 780.

A processor 790 is coupled to each of the five spectrometers 772, 774,776, 778, and 780 by data cables 782, 784, 786, 788, and 789 and furtheranalyzes the combined light energy received by the spectrometers. Theprocessor 790 then compares these results to a predetermined orpre-assigned value that represents an acceptable measurement of thepackage (i.e. a package with an acceptable level of defects). Thecomparison value can either be obtained by a calibration run asdescribed above or can be input into the processor based on knownvalues. If the defect level does not conform to the comparison value, arejection unit 794 coupled to the processor sends a signal to thepackaging line to discard or remove the package with the defect.

Turning to FIG. 6, a diagrammatic representation of a further aspect ofan inspection system constructed in accordance with the presentinvention is shown. FIG. 6 shows in further detail a diagrammaticrepresentation of the lower portion of an inspection head 110 used inconjunction with an inspection system, and more particularly, an arrayof sample probes and how they interact with the tablets passing along aconveyer. The probe array is generally referred to in FIG. 6 asreference number 800. In the example of FIG. 6, a product package 815,such as a filled but yet un-sealed blister package, contains fifteen(15) individual tablets in a three-by-five arrangement. Various otherarrangements of the tablets are contemplated and the three-by-fivearrangement of FIG. 6 is shown merely as an example. The tablets in thepackage 815 are arranged into five columns, each having three rows. Fromleft to right in FIG. 6, column one includes tablets 825 a, 825 b, and825 c, column two contains tablets 830 a, 830 b, and 830 c, column threecontains tablets 835 a, 835 b, and 835 c, column four contains tablets840 a, 840 b, and 840 c, and column five contains tablets 845 a, 845 b,and 845 c. Corresponding to each of the fifteen tablets in the exampleof FIG. 6 is a sample probe. From left to right, the sample probes arealso divided into five columns with three sample probes in each column.Column one contains sample probes 925 a, 925 b, and 925 c, column twocontains sample probes 930 a, 930 b, and 930 c, column three containssample probes 935 a, 935 b, and 935 c, column four contains sampleprobes 940 a, 940 b, and 940 c, and column five contains sample probes945 a, 945 b, and 945 c. As the conveyer system moves the package 815into position under the inspection head 110, the fifteen sample probesare positioned to correspond respectively to a similarly positionedtablet in the package 815. Namely, the samples probes are positionedsubstantially above the correspondingly positioned tablet.

Each of the sample probes are connected to a pair of fiber optic cableswhich in turn are connected to one of five different column light energyaggregators 950, 960, 970, 980, or 990 and to one of three different rowlight energy aggregators 1080, 1090, or 1100. Thus, each sample probe isconnected to one column light energy aggregator and to one row lightenergy aggregator. In FIG. 6, the thirty fiber optic cables connectingthe sample probes to the eight light energy aggregator are representedas reference numbers 850, 855, 860, 865, 870, 875, 880, 885, 890, 895,900, 905, 910, 915, 920 (corresponding to the column light energyaggregators), 1000, 1005, 1010, 1015, 1020, 1025, 1030, 1035, 1040,1045, 1050, 1055, 1060, 1065, and 1070 (corresponding to the row lightenergy aggregators). Each one of these thirty fiber optic cablescorresponds to a single sample probe and thus also corresponds to alight reading from a single tablet passing beneath the inspection head.Since there are two fiber optic cables for each sample probe, a readingfrom a particular sample probe is passed to both a column light energyaggregator and to a row light energy aggregator.

Each of the light energy aggregators 950, 960, 970, 980, 990, 1080,1090, and 1100 operate to combine the light energy gathered by thesample probes (via the fiber optic cables) that feed light energy intoit. Each light energy aggregator then outputs the combined light energythrough a single output terminal. In the embodiment of FIG. 6, each ofthe light energy aggregators 950, 960, 970, 980, and 990 is associatedwith the fiber optic cables and sample probes from a single column,while each of the light energy aggregators 1080, 1090, and 1100 isassociated with the fiber optic cables and sample probes from a singlerow. More specifically, light energy aggregator 950 receives lightenergy input from fiber optic cables 850, 855, and 860, light energyaggregator 960 receives light energy input from fiber optic cables 865,870, and 875, light energy aggregator 970 receives light energy inputfrom fiber optic cables 880, 885, and 890, light energy aggregator 980receives light energy input from fiber optic cables 895, 900, and 905,and light energy aggregator 9 90 receives light energy input from fiberoptic cables 910, 915, and 920. Light energy aggregator 1080 receiveslight energy input from fiber optic cables 1000, 1005, 1010, 1015, and1020, light energy aggregator 1090 receives light energy input fromfiber optic cables 1025, 1030, 1035, 1040, and 1045, and light energyaggregator 1100 receives light energy input from fiber optic cables1050, 1055, 1060, 1065, and 1070.

Further details of a preferred embodiment of a light energy aggregatorconstructed in accordance with the present invention are described inconjunction with FIGS. 8-12. Briefly, the combined light energy fromeach of the light energy aggregators 950, 960, 970, 980, 990, 1080,1090, and 1100 is directed to an entrance slit on a correspondingspectrometer 955, 965, 975, 985, 995, 1085, 1095, or 1105 where it issubsequently analyzed. Light sources 820 a and 820 b illuminate thetablets as they pass beneath the sample probes.

In operation, the inspection head allows a system to evaluate whetherone of the fifteen tablets in the package 815 are misplaced, defective,missing, chemically non-conforming, or has another problem. As thepackaging system begins a run, reflectance data is acquired from a knownrepresentative sample package of tablets as they pass beneath the tipsof the sample probes and statistics are compiled based on the combinedspectra of the items being inspected. The representative package is of aknown quality and this initial run is thus classified as a calibrationrun. Preprocessing of the spectra is applied in a similar manner asdescribed above in conjunction with FIG. 2, however, information isgathered on a column-by-column and row-by-row basis rather than on awhole-package-basis as in the embodiment of FIG. 2. In this manner, if adefect or other abnormality is discovered within the package 815, thelocation of the defect can be narrowed down to a particular row and aparticular column within the package allowing precise segregation of thedefective component and allowing all of the conforming tablets to beutilized in a subsequent packaging run. Less waste and higher throughputis therefore realized.

Turning to FIG. 7, a schematic diagram of an inspection system 1200constructed in accordance with the present invention is shown. Theschematic diagram of FIG. 7 generally corresponds to FIG. 6. The diagramof FIG. 7 represents how a number of different sample probesP_(A1)-P_(E3) can be utilized to obtain a spectrographic measurementfrom any number of individual samples on a row-by-row andcolumn-by-column basis. The collected row information is fed through arow specific light energy aggregator to a row-specific spectrometer as acombined input and the collected column information is fed through acolumn specific light energy aggregator to a column-specificspectrometer as a combined input. Based on the combined reading from thesample probes corresponding to each row and the sample probescorresponding to each column, an evaluation can be made as to whether adefect (either chemical or physical) exists somewhere in the package. Afurther determination can be made as to which row and column the defector other abnormality resides, and therefore, the precise location of thenon-conforming item can be ascertained. Since a combined value isobtained for each row and column of tablets, a particular row as a wholeor a particular column as a whole is analyzed for a defect rather thaneach particular tablet. If a particular row or particular column as awhole is determined to have a defect, the entire package can be rejectedbut the conforming tablets can be salvaged and stored for later reuse orbe automatically placed back into the packaging line for insertion intoa subsequent package. Utilizing such a system allows faster analysiswhile utilizing a fewer number of spectrometers thereby making thesystem as a whole less expensive and easier to maintain.

With continuing reference to FIG. 7, each of the fifteen sample probesP_(A1) through P_(E3), represented by reference numbers 1202, 1204,1206, 1208, 1210, 1212, 1214, 1216, 1218, 1220, 1222, 1224, 1226, 1228,and 1230 are connected to a pair of corresponding fiber optic cables.The fiber optic cables corresponding to the five columns of sampleprobes are shown as reference numbers 1232, 1234, 1236, 1238, 1240,1242, 1244, 1246, 1248, 1250, 1252, 1254, 1256, 1258, and 1260respectively. The fiber optic cables corresponding to the three rows ofsample probes are shown as reference numbers 1302, 1304, 1306, 1308,1310, 1312, 1314, 1316, 1318, 1320, 1322, 1324, 1326, 1328, and 1330respectively. The subscript designation in each of the probe labelsrefer to the column and row of each probe. Namely, the letterdesignations, A, B, C, etc. refer to the first, second, third, etc.columns and the number designations 1, 2, and 3 refer to the rowdesignation in each column. Each of the array of fifteen sample probescan thus be uniquely represented.

The column-by-column grouping of fiber optic cables are connected to acorresponding column light energy aggregator 1262, 1264, 1266, 1268, and1270, and the row-by-row groupings of fiber optic cables are in turnconnected to a corresponding row light energy aggregator 1332, 1334, and1336. Each of the light energy aggregators operate to combine the lightenergy gathered by the fiber optic cables from a particular column orrow and output the combined light energy through a single outputterminal. Further details of a preferred embodiment of a light energyaggregator constructed in accordance with the present invention aredescribed in conjunction with FIGS. 8-12. Briefly, and as shown in FIG.7, the combined output light energy from the column light energyaggregator 1262 is directed through a single fiber optic cable 1272 andthrough an entrance slit 1273 to a spectrometer 1282. The combined lightenergy is subsequently analyzed by the spectrometer 1282. The combinedoutput light energy from the column light energy aggregator 1264 isdirected through a single fiber optic cable 1274 and through an entranceslit 1275 to a spectrometer 1284. The combined light energy issubsequently analyzed by the spectrometer 1284. The combined outputlight energy from the column light energy aggregator 1266 is directedthrough a single fiber optic cable 1276 and through an entrance slit1277 to a spectrometer 1286. The combined light energy is subsequentlyanalyzed by the spectrometer 1286. The combined output light energy fromthe column light energy aggregator 1268 is directed through a singlefiber optic cable 1278 and through an entrance slit 1279 to aspectrometer 1288. The combined light energy is subsequently analyzed bythe spectrometer 1288. The combined output light energy from the columnlight energy aggregator 1270 is directed through a single fiber opticcable 1280 and through an entrance slit 1281 to a spectrometer 1290. Thecombined light energy is subsequently analyzed by the spectrometer 1290.

Similarly, the combined output light energy from the row light energyaggregator 1332 is directed through a single fiber optic cable 1338 andthrough an entrance slit 1339 to a spectrometer 1344. The combined lightenergy is subsequently analyzed by the spectrometer 1344. The combinedoutput light energy from the row light energy aggregator 1334 isdirected through a single fiber optic cable 1340 and through an entranceslit 1341 to a spectrometer 1346. The combined light energy issubsequently analyzed by the spectrometer 1346. The combined outputlight energy from the row light energy aggregator 1336 is directedthrough a single fiber optic cable 1342 and through an entrance slit1343 to a spectrometer 1348. The combined light energy is subsequentlyanalyzed by the spectrometer 1348.

A processor 1360 is coupled to each of the eight spectrometers 1282,1284, 1286, 1288, 1290, 1344, 1346, and 1348 by data cables 1292, 1294,1296, 1298, 1300, 1350, 1352, and 1354 respectively. The processor 1360further analyzes the combined light energy received by thespectrometers. The processor 1360 then compares these results to apre-determined or pre-assigned value that represents an acceptablemeasurement of the package (i.e. a package with an acceptable level ofdefects). The comparison value can either be obtained by a calibrationrun as described above or can be input into the processor based on knownvalues. If the defect level does not conform to the comparison value, arejection unit 1365 coupled to the processor 1360 sends a signal to thepackaging line to discard or remove the package containing the defect.

FIG. 8 shows a general schematic representation of a light energyaggregator 1500 utilized in an inspection system constructed inaccordance with the present invention. The light energy aggregator 1500collects the light signals transmitted by a number of fiber optic inputcables, aggregates the light signals, and transmits the aggregated lightsignals as a single light energy output. Preferably, the light energyoutput represents an average reflectance value obtained through theseveral fiber optic input cables. The light energy aggregator 1500includes a housing 1535 having an input end 1536 and an output end 1538.The input end 1536 includes input terminals 1520, 1522, 1524, 1526, and1528 which connect fiber optic input cables 1502, 1504, 1506, 1508, and1510 respectively to the light energy aggregator housing 1535. A feweror greater number of input terminals also are contemplated. The inputterminals are preferably an SMA or other type of known fiber opticconnection device. The output end 1538 includes a single output terminal1532 connected to an output fiber optic cable 1530. Alternatively, theindividual light input optical fibers 1502-1510 may be combined into thesingle output bundle 1530 without the use of any intervening fiber opticconnectors.

FIGS. 9-12 show a preferred embodiment of a light energy aggregatorutilized in accordance with the present invention. The light energyaggregator embodied in FIGS. 9-12 utilizes a splitter block 1540. Inconjunction with an inspection system constructed in accordance with thepresent invention, sample probes 1550 and 1555 take light energyreadings from an item to be sampled and bring the collected light energyto the splitter block 1540. Each of the two sample probes 1550 and 1555in FIG. 9 contain two fiber optic strands 1553 and 1554 (See crosssection in FIG. 10). The fiber optic strands 1553 and 1554 are encasedin an insulating and non-light transmitting material 1552. The entireprobe 1550 is contained in a PVC sheathing 1551. Connection devices 1560and 1565 connect each of the sample probes to a flexible tube 1570 or1575 which can be directed to an input end 1542 of the splitter block1540. While the light energy aggregator shown in FIGS. 9-12 utilizes twosample probes, it is contemplated that any number of sample probes andcorresponding fiber optic strands can be utilized in an inspectionsystem constructed in accordance with the present invention.

Again referring to FIG. 9, the splitter block 1540 includes a singlebundled cable 1580 coupled to an output end 1544 of the splitter block1540. The cable 1580 leads to a spectrometer connector 1590 having aspectrometer input tip 1595. In conjunction with the splitter block1540, the input tip 1595 functions to bring all of the collected lightenergy from each of the sample probes (in this case 1550 and 1555) to aspectrometer. The input tip 1595 is therefore adapted to engage with alight entrance slit of a spectrometer.

FIG. 11 shows a cross-section of the splitter block 1540. While thecross-section of FIG. 11 is representative of the splitter block shownin FIG. 9, nine probe connections are shown rather than the two embodiedin FIG. 9. The nine probe connections 1600, 1602, 1604, 1606, 1608,1610, 1612, 1614, and 1616 are substantially identical in structure,each including two separate fiber optic strands. The splitter block 1540combines the eighteen (18) total fiber optic strands engaging the inputend 1542 of the splitter block into a single bundled cable 1580 engagingthe output end 1544. The bundled cable 1580 is preferably covered with aPVC sheathing 1585. FIG. 12 shows a cross section of the input tip 1595of the bundled cable 1580 as it is adapted to align and couple with theentrance slit of a spectrometer.

The splitter block embodiment of a light energy aggregator depicted inFIGS. 9-12 is one example of such a light energy aggregator and otherembodiments of a device that combines the light energy from two or moresample probes are contemplated by the present invention. For example,another embodiment of a light energy aggregator uses a reflectivechamber to receive collected light energy from each of the sampleprobes. As all of the light energy is combined within the light chamber,a single output distributes the aggregated light energy and directs itthrough a single fiber optic strand. This single fiber optic strand isthen directed to the entrance slit of a spectrometer. Such an embodimentof a light energy aggregator is beneficial since it reduces thecomplexity of the entrance slit connection. The reflective chamber ispreferably highly polished, such as a gold plated finish orelectro-polished stainless steel, so that light energy losses are keptto a minimum.

FIGS. 13-15 show a preferred embodiment of an inspection head 1700 as itmounts over a conveyer-based packaging line and inspection system. Theinspection head 1700 includes a probe housing 1715 mounted over aconveyer unit 1710. The conveyer unit 1710 includes a pair of channels1712 and 1714 that are adapted to carry, for example, filled blisterpackages past the inspection head 1700 and its associated sample probes.The inspection head 1700 also includes near-infrared light sourcehousings 1725 a and 1725 b mounted on either side of the conveyer unit1710. The two housings 1725 a and 1725 b contain a near-infrared lightsource that is directed at the channels 1712 and 1714 where the items tobe inspected travel. It is contemplated that in other embodiments, thenumber of channels in the conveyer unit 1710 may be more or less thantwo.

In FIG. 14, a front faceplate of the probe housing is removed toillustrate the arrangement of an array of sample probes 1730. Generally,the sample probes 1730 are positioned so that they each align with asingle item in a package 1716 passing beneath. FIG. 14 is shown withfour individual sample probes corresponding to each of the packages1716, since each of the packages contain four items in FIG. 14. Ofcourse, in a system adapted to inspect packages with a different numberof items, a corresponding number of sample probes would be included.Preferably, the probe housing 1715 can be easily retooled to accommodatea varying number of sample probes, for example, probe housing moduleshaving a set number of sample probes can be utilized to easily changethe format of the inspection head. Also, a probe mounting plate that hasa pattern of holes for holding the probes positioned above each of theitems may be utilized. The probe mounting plate may be adapted to beeasily changed to accommodate a different layout of items. Pre-assembledsample probe manifolds can also be utilized to accomplish the goal of aneasy exchange for use with different packaging and inspection systemsthat utilize varying sized packages. An array of fiber optic cables 1740connects each of the sample probes to a spectrometer housing 1720mounted above the sample probe housing 1715.

FIG. 15 shows a cross section of the inspection head 1700 and moreparticularly the connections between the sample probes 1730, the fiberoptic cables 1740, a light energy aggregator 1750 and a spectrometer1760. Preferably, the light energy aggregator 1750 and the spectrometer1760 are both mounted within the spectrometer housing 1720 although itis contemplated that the light energy aggregator may be positionedelsewhere in the inspection head 1700. It is also contemplated that thelight aggregator 1750 and/or the spectrometer 1760 may be locatedoutside of the inspection head 1700. FIG. 15 illustrates how the sampleprobes 1730 align with each of the items contained in the package 1716and combine the signal gathered by the probes in the light energyaggregator 1750. The combined signal is then transferred to thespectrometer 1760 for processing.

FIGS. 16 and 17 present several flow charts describing methods ofinspection and analyzing reflectance data in accordance with the presentinvention. In FIG. 16, a method 1800 includes illuminating a target orpackage at 1810 and then obtaining a reference reflectance value forthat package at a 1820. The reference reflectance value can be obtainedeither by a calibration run 1825 or by inputting the known values at1830.

After the reference reflectance value is obtained, reflected light iscollected at 1835 from all items in the target package. This reflectedlight is combined at 1840 and input into a spectrometer at 1845 wherethe light energy is measured and the reflectance calculated at 1850. Acomparison is made between the reference reflectance value and theacquired reflectance value at 1855 and a determination is made at 1860whether the acquired reflectance data falls within the reference dataacceptance criteria. If the acquired reflectance data is acceptable theprocess continues at 1865, a next target or other sample is prepared at1875 and the process repeats at 1890. If the acquired reflectance datais not within acceptable criteria, the target package is rejected at1870, a next target or other sample is prepared at 1875, and the processrepeats at 1890.

Turning to FIG. 17, a method 1900 includes illuminating a target orpackage at a 1905 and then obtaining a reference reflectance value forthat package at 1910. The reference reflectance value can be obtainedeither by a calibration run 1915 or by inputting the known values at1920. At 1925, item-by-item reflected light is collected, and then adetermination is made at 1930 whether more detailed information aboutthe package reflectance data is required, i.e. whether column-by-columnor row-by-row reflectance data is desired. If the more detailedreflectance data is required, then the column data is sorted at 1935,the row data is sorted at 1940 and the row and column data are combinedat 1945. The combined reflected light is then input into a spectrometerat 1955. If row and column specific information is not required thenreflected light is combined for all of the items in the package at 1950,and the combined reflected light is input into a spectrometer at 1955.

The light energy is measured and reflectance calculated at 1960, acomparison is made between the reference reflectance value and theacquired reflectance value at 1965, and a determination is made at 1970whether the acquired reflectance data falls within the reference dataacceptance criteria. If the acquired reflectance data is acceptable theprocess continues at 1975, a next target is prepared for inspection, andthe process repeats.

If the acquired reflectance data is not acceptable a furtherdetermination is initiated at 1980 to isolate the location of thenon-conforming item or items within the package. Once the non-conformingitem or items are located, the target package is rejected at 1985 andthe location data is sent to a user for further processing or analysisat 1990. Alternately, the rejected package is automatically sorted andthe conforming items are reinserted into the packaging system. Theinspection process continues by preparing a next target for inspectionand repeating the inspection process.

As mentioned above, an inspection device constructed in accordance withthe present invention is preferably used in conjunction with apharmaceutical packaging system, although it is contemplated that suchan inspection system can be used with a variety of other applicationssuch as food manufacturing/packaging, consumer goods, as well asindustrial applications.

The methods and systems outlined above for inspecting and analyzingpackaged items utilize an individual sample probe to collect thereflected light from each item in the package. The sample probes in theabove examples and embodiments are aligned with the individual items inthe package. This technique is most applicable when the location withinthe package of the item being analyzed is well known, such as when astandardized packaging unit is used, i.e. a blister pack for a regularlyprocessed pharmaceutical. Other examples include oral contraceptivepackaging, antihistamine packaging, and vitamin packages where multipledosage formats are included in a single package, e.g. day and nightantihistamine dosages or contraceptive dosages.

For situations where the location within the package of each item is notpre-determined, the concepts of imaging spectrometry may be utilized inaccordance with an embodiment of the present invention to identify theindividual item locations. In addition to identifying the item locationwithin a package, an imaging spectrometer can be simultaneously used inaccordance with an embodiment of the present invention to capture thespectrum of the individual items for analysis.

Imaging spectrometers simultaneously capture data in as many as hundredsof contiguous registered spectral bands, such that a spectral vectorcontaining as much information as an individual spectrometer spectrum ismeasured for each picture element (pixel). The field of view of animaging spectrometer may be considered as a collection of pictureelements (pixels) or resolution elements (reselms). This field can beimaged onto an array of detector elements in a focal plane array (FPA),or it may be imaged by a single detector or small array that is scannedover the field. Further information and details regarding imagingspectrometers can be found in Introduction to Imaging Spectrometers,William L. Wolfe, 1997, wich is hereby incorporated by reference.

Generally, in a push-broom scanning-type imaging spectrometer, thespectral data is acquired one image line at a time. By moving the itemsto be scanned underneath the imaging element a second spatial dimensionis provided, a two dimensional spatial image can be developed with athird spectral dimension. With a complete image field of a packageobtained, identification and isolation of individual items within thepackage of items can be made by comparing the spectra obtained at eachpixel with the corresponding pixel from a known background, i.e. anunfilled package. After the pixels corresponding to the filled packageand the product items within the package have been isolated, any one ofthe analyses described above in conjunction with FIGS. 1-17 can beapplied to determine whether the package items conform to apre-determined standard.

A push broom imaging spectrometer (IS) is one that uses a 2-D detectorarray. One dimension of the detector is used to collect the spatialinformation (i.e. it images a row of spatial pixels corresponding to thevarious positions across the conveyor transporting the items by thehead) and the other is used to collect the spectral information (i.e.each column of the array simultaneously measures the spectrumcorresponding to a single spatial pixel). The image is acquired one lineat a time. Optics are used to project an image of the surface underobservation onto the entrance slit of the IS. The height of the entranceslit defines the height of the spatial pixels in the final image. Insidethe IS, the dispersed image of the light transmitted through theentrance slit is focused onto the 2-D detector array. The wide dimensionof the entrance slit is focused across the width of the detector array.Thus, the width of the detector in pixels is equal to the width of thespatial image in pixels.

The grating disperses the light perpendicular to the wide dimension ofthe entrance slit. Thus, the other dimension of the detector is used tocollect the spectral information. The number of wavelengths measuredcorresponds to the dimension of the detector in this direction.

The second spatial dimension is acquired by moving the sensor relativeto the surface under observation. The end result is a 3-D data set: 2spatial and one spectral dimension.

Standard image analysis routines are used to define the centers of theitems under inspection. Spectra corresponding to these center pixels(one or more pixels averaged for each item depending on the size of theitem and the size of the spatial pixels) are then analyzed in the samemanner as the non-IS example. Also note that because a complete image isacquired, the IS-based approach also provides the shape of the itemsunder inspection.

With reference to FIG. 18, a push-broom scanning imaging spectrometersystem 2000 constructed in accordance with an embodiment of the presentinvention is shown. The imaging spectrometer system 2000 is preferablyused to obtain item-location data corresponding to a package 2030 thatcontains, for example, an array of items 2040. As an example, thepackage 2030 may comprise a blister pack that includes an array oftablet wells shaped and sized to each hold an individual tablet. Thespectrometer system 2000, includes an imaging spectrometer 2010 and afore-optics unit 2015. The push broom scanning spectrometer 2000 ismounted above a conveyer system 2020 that carries the package 2030through a field of view 2017 of the fore-optics unit 2015. The conveyersystem 2020 is similar to those described in conjunction with FIGS.1-15.

Also shown on the conveyer 2030 is an unfilled, or “blank” package 2025.The blank package 2025 in FIG. 18 also shows empty tablet wells 2035.The direction of the conveyer movement is indicated by an arrow 2027 andillustrates how the blank package 2025 passes the imaging element 2015first, thereby providing a reference image. When the filled package 2030passes the imaging element 2015, the spectral data gathered can becompared to the reference image previously obtained and a determinationcan be made as to the specific locations of the individual items 2040within the package 2030.

Preferably, there are two reference images. The first without items inplace, the second with items in place. These reference images can thenbe used to indicate the general location of each item with the specificlocation determined by standard image processing methods applied to thenew image of each group of items. Alternatively, the system can use thereference image (this time only with the tablets in place) to train thesystem to recognize the items wherever they are located within thesystem's field-of-view.

FIGS. 19A-19C show a plan view representing the product packages thatcorrespond to the embodiment of FIG. 18. FIG. 19A shows a blank package2100 having a four-by-four array of item locations 2110. Each itemlocation includes a tablet well 2115. FIG. 19B shows a filled package2125. The arrangement of the package 2125 is identical to that of thepackage 2100 except that tablets 2130 are loaded into each of the tabletwells 2115. Finally, FIG. 19C illustrates how the imaging spectrometerscans the package 2125 one image line at a time. A single row of imagepixels 2160 is scanned in a given time frame by the spectrometer. As thepackage 2125 passes beneath the scanning element, sequential rows ofimage pixels are scanned until an array of pixels 2155 is formed. Thearray 2155 represents an image of the package 2125. The package image isthen compared to the reference image previously obtained and the itemlocations can be precisely ascertained.

FIG. 20 depicts a scanning method 2200 in accordance with an embodimentof the present invention. The spectral reference images of both a blank,unloaded package, and a filled package are first obtained at 2210. Thespectral image of a package under inspection is obtained at 2215.Obtaining the spectral image of a package under inspection 2215 is shownin more detail in FIG. 20 as collecting the first line of the image at2220, incrementing the position of the package at 2222, and looping backto 2220 until the complete image is acquired at 2224. The referencespectral image(s) are compared with the spectral image of the packageunder inspection at 2230, the item locations are then determined, andthe image pixels corresponding to the item locations are isolated at2240. Spectral analysis of the item compositions can then beaccomplished by any of the methods and systems previously described andillustrated as well as by other known inspection systems and methods.

Although the present invention has been described and illustrated in theabove description and drawings, it is understood that this descriptionis by example only and that numerous changes and modifications can bemade by those skilled in the art without departing from the true spiritand scope of the invention. The invention, therefore, is not to berestricted, except by the following claims and their equivalents.

1. A push-broom scanning spectrometer, comprising: an imager adapted tosimultaneously acquire a line of image pixel from a moving package,wherein the image pixel line comprises a plurality of contiguou spectralbands, wherein the image pixel line is oriented perpendicular to thedirection of motion of the package, wherein the package includes aplurality of items; a conveyer system adapted to move the packagethrough field of view corresponding to the imager; and a processorcapable of being programmed to compare the line of image pixels with areferences signal and to determine the location of the plurality ofitems within the package based on the comparison of the line of imagepixels to the reference signal.
 2. The push-broom scanning spectrometerof claim 1, wherein the imaging element is a two-dimensional array ofphoto-detectors.
 3. The push-broom scanning spectrometer of claim 1,wherein the line of image pixels corresponds to a plurality of pixelelements.
 4. The push-broom scanning spectrometer of claim 1, whereinthe scanning spectrometer is incorporated into a pharmaceuticalpackaging system.
 5. The scanning spectrometer of claim 1, wherein theprocessor is further capable of being programmed to determine thechemical composition of at leas one of the items in the package.
 6. Thescanning spectrometer of claim 1, wherein the processor is furthercapable of being programmed to determine the chemical composition of theplurality of items in the package.
 7. A push-broom scanningspectrometer, comprising: an imager adapted to simultaneously acquireline of image pixels from a moving package, wherein the image pixel linecomprises a plurality of contiguous spectral bands, wherein the imagepixel line is oriented perpendicular to the direction of motion of thepackage, wherein the package includes a plurality of items having achemical composition, and wherein the plurality of contiguous spectralbands corresponds to the chemical composition of the plurality of items;a conveyer system adapted to move the through a field of viewcorresponding to the imager; and a processor capable of being programmedto compare the line of image pixels with a references signal and todetermine the location of the plurality of items within the packagebased on the comparison of the line of image pixels to the referencesignal.
 8. The scanning spectrometer of claim 7, wherein the processoris further capable of being programmed to determine the chemicalcomposition of the plurality of items based on the comparison of theline of image pixels to the reference signal.
 9. A method of determiningthe location of a plurality of items within a package using a scanningspectrometer, comprising: acquiring a line of image pixels from a movingpackage through an imager, wherein the image pixel line comprises aplurality of contiguous spectral bands, wherein the image pixel line isoriented perpendicular to the direction of motion of the package andwherein the package includes a plurality of items having a chemicalcomposition and wherein the plurality of contiguous spectral bandscorresponds to the chemical composition of the plurality of items;moving the package through a field of view of the imager; comparing theline of image pixels with a reference signal; and determining thelocation of the plurality of items within the package based on thecomparison of the line of image pixels to the reference signal.
 10. Themethod of claim 9 further comprising determining the chemicalcomposition of at least one of the plurality of items.
 11. The method ofclaim 9 further comprising determining the chemical composition of theplurality of items.
 12. The method of claim 9 wherein the package is ablister pack.
 13. The method of claim 9 wherein the plurality of itemsare sealed within the package.
 14. The method of claim 9 furthercomprising storing information corresponding to the location of at leastone of the plurality of items.